ViewPager+Fragment避免重复createview

每次使用ViewPager+Fragment来作为app的框架的时候都要格外小心，因为他们的生命周期有点奇怪，并没有Activity那样来得自然。如何奇怪呢，请看下面日志

打开app，一开始为第一个Fragment02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1 setUserVisibleHint.isVisibleToUser=false02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2 setUserVisibleHint.isVisibleToUser=false02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1 setUserVisibleHint.isVisibleToUser=true02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onAttach02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onCreate02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onAttach02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onCreate02-09 14:02:12.551 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onCreateView02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onActivityCreated02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis W/FragmentManager: moveToState: Fragment state for MainFragment2{5434690 #0 id=0x7f0c0056 android:switcher:2131492950:1} not updated inline; expected state 3 found 202-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onCreateView02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onActivityCreated02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onStart02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onResume02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onStart02-09 14:02:12.561 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onResume切换到第二个Fragment02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3 setUserVisibleHint.isVisibleToUser=false02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1 setUserVisibleHint.isVisibleToUser=false02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2 setUserVisibleHint.isVisibleToUser=true02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onAttach02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onCreate02-09 14:03:21.981 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onCreateView02-09 14:03:21.991 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onActivityCreated02-09 14:03:21.991 30159-30159/com.tianjiyun.glycuresis W/FragmentManager: moveToState: Fragment state for MainFragment3{863ec84 #2 id=0x7f0c0056 android:switcher:2131492950:2} not updated inline; expected state 3 found 202-09 14:03:21.991 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onStart02-09 14:03:21.991 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onResume切换到第三个Fragment02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4 setUserVisibleHint.isVisibleToUser=false02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2 setUserVisibleHint.isVisibleToUser=false02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3 setUserVisibleHint.isVisibleToUser=true02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onAttach02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onCreate02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onPause02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onStop02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onDestroyView02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onCreateView02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onActivityCreated02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis W/FragmentManager: moveToState: Fragment state for MainFragment4{6fa481c #3 id=0x7f0c0056 android:switcher:2131492950:3} not updated inline; expected state 3 found 202-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onStart02-09 14:04:54.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onResume切换到第四个Fragment02-09 14:05:30.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3 setUserVisibleHint.isVisibleToUser=false02-09 14:05:30.941 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4 setUserVisibleHint.isVisibleToUser=true02-09 14:05:30.951 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onPause02-09 14:05:30.951 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onStop02-09 14:05:30.951 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onDestroyView最后且回到第一个Fragment02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1 setUserVisibleHint.isVisibleToUser=false02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2 setUserVisibleHint.isVisibleToUser=false02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4 setUserVisibleHint.isVisibleToUser=false02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1 setUserVisibleHint.isVisibleToUser=true02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onCreateView02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onActivityCreated02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onStart02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment1onResume02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onCreateView02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onActivityCreated02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis W/FragmentManager: moveToState: Fragment state for MainFragment2{5434690 #0 id=0x7f0c0056 android:switcher:2131492950:1} not updated inline; expected state 3 found 202-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onStart02-09 14:06:05.651 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment2onResume02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onPause02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onStop02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment3onDestroyView02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onPause02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onStop02-09 14:06:06.101 30159-30159/com.tianjiyun.glycuresis V/Kuby_test: MainFragment4onDestroyView

一般createView都是一次就行了，因为有时候请求网络啊，或者一些数据已经改变了，后来再切回来就恢复了初始状态。Android官方为了性能，做了这样的灵活设置，切换到下一个fragment的时候会预加载相邻的Fragment，然后把不相邻的都销毁掉，切回被销毁掉的Fragment的时候又会重新createView一次。这样做可能性能得到提高，可是实际开发中却显得有点不方便，也许是我没有领会到更高级的写法。那么我只想要他们老老实实的像Activity一样怎么办呢？这就是这篇文章的目的

解决办法：

具体情况看我写的这个demo，自定义了一个Fragment的超类BaseFragment，只要继承这个BaseFragment，不要复写生命周期，复写几个方法就可以了。使用情况请看上面的注释。

下载地址：http://download.csdn.net/detail/u014736095/9750716

很多时候开发者我为了方便使用了show和hind的方法去控制他们，因为这样可以解决viewpager的预加载问题。但是这样没有切换动画，如重Fragment1切换到Fragment4，用show和hind就不会按照1.2.3-->4这样的切换动画，而是1-->4。